In minutes, the blood transports the alcohol to all parts of the body, including the brain. Alcohol affects the brain’s neurons in several ways. It alters their membranes as well as their ion channels, enzymes, and receptors. Alcohol also binds directly to the receptors for acetylcholine, serotonin, GABA, and the NMDA receptors for glutamate.
Your Structure, Your Self. Packaging, Transport and Final Processing of the Endorphin Propeptides. Demystifying DNA Demethylation. Genetics Home Reference - Your guide to understanding genetic conditions.

Pauling2.htm. Moreover, the process of natural selection may be expected later on to lead to the survival of a species or strain that synthesizes somewhat less than the optimum amount of an autotrophic vital substance rather than of the species or strain that synthesizes the optimum amount.

To synthesize the optimum amount requires about twice as much biological machinery as to synthesize half the optimum amount. As suggested in Fig. 1, the evolutionary disadvantage of synthesizing a less than optimum amount of the vital substance may be small, and may be outweighed by the advantage of requiring a smaller amount of biological machinery. Evidence from the study of microorganisms is discussed in the following paragraphs. Many mutant microorganisms are known to require, as a supplement to the medium in which they are grown, a substance that is synthesized by the corresponding wild-type organism (the normal strain).